In order to improve the aerodynamic performance of a helicopter main rotor, and/or reduce the vibration level of the blades of such a rotor, and/or the noise emitted by the blades of a rotating rotor, it has already been proposed to superpose, on the standard cyclic pitch control of the blades, necessary for the control of a helicopter main rotor and for the attitude control of the helicopter, a multi-cyclic control, with a frequency a multiple of the rotational frequency of the rotor.
However, a multi-cyclic control requires substantial modification of the structure and the operation of the standard swash-plate devices, with which practically all helicopters are fitted for the control of the collective and cyclic pitch of the blades.
The problem at the basis of the invention is to propose an improved blade, intended for the fitting in particular to helicopter main rotors, and allowing these rotors to obtain approximately the same advantages as a multi-cyclic pitch control, without requiring modification of the structure and operating mode of a standard swash-plate pitch control device.
Another problem at the basis of the invention is to propose, for the operation of at least one trailing edge air flow control flap of a blade, an actuating assembly or actuator gear mounted on the blade and including, between at least one actuator of this gear and the control flap, a transmission of simple, economic, reliable structure occupying little space, and capable of being combined with different types of actuators.